Efficient single-emitting layer hybrid white organic light-emitting diodes with low efficiency roll-off, stable color and extremely high luminance

An efficient single-emitting layer hybrid white organic light-emitting diode (WOLED) was developed, simultaneously fulfilling low efficiency roll-off, stable color and extreme luminance. At the practical luminance of 1000 cd/m(2), a total current efficiency of 42.8 cd/A and power efficiency of 19.2 lm/W are achieved, maintaining as high as 40.5 cd/A and 15.5 lm/W even at 5000 cd/m(2). Besides, a slight color variation [(0.025, 0.011)] and extreme luminance (similar to 10(6) cd/m(2)) are obtained. The working mechanism is unveiled and it is demonstrated that the triplet-exciton-confining ability of electron transport layers plays a more vital role in device performances, particularly for the lifetime. (C) 2015 The Korean Society of Industrial and Engineering Chemistry. Published by Elsevier B.V. All rights reserved.